Method of three-dimensional printing

ABSTRACT

A sustainable material suitable for three-dimensional printing is disclosed. The sustainable material comprises a resin derived from a bio-based diacid monomer and a bio-based glycol monomer. The resulting sustainable material provides a much more robust 3-D printing material with different properties than conventional materials.

TECHNICAL FIELD

The present embodiments relate to three-dimensional (3-D) printing. Morespecifically, there is provided a sustainable bio-based composition foruse in applications related to printing 3-D objects, ink compositionscomprising the sustainable bio-based composition for printing 3-Dobjects and methods of using the same.

BACKGROUND

Three-dimensional (3-D) printing has been a popular method of creatingvarious prototypes. There are several different methods of 3-D printing,but the most widely used and the least expensive is a process known asFused Deposition Modeling (FDM). FDM printers use a thermoplasticfilament, which is heated to its melting point and then extruded, layerby layer, to create a three dimensional object.

FDM printers use a printing material, which constitutes the finishedobject, and a support material, which acts as a scaffolding to supportthe object as it is being printed. The most common printing material forFDM is acrylonitrile butadiene styrene (ABS) which is a thermoplasticand has a glass transition temperature of about 105° C. Another commonprinting material for FDM is poly-lactic acid (PLA) which is abiodegradable thermoplastic aliphatic polyester derived from renewableresources and has a glass transition temperature 60-65° C. Both ABS andPLA are easily melted and fit into small molds. These plastics typicallymust be heated to between 180 to 260° C. in order to melt. Concerns havebeen raised over health issues associated with decomposition of thethermoplastics during heating, such as ABS at, wherein it can releasevolatile organic compounds (VOCs) such as styrene, ethylbenzene, andacrylonitrile during heating. PLA, also has issues with the removal fromsupport material, as well as moisture absorption, bubble spurting at thenozzle, discoloration and reaction with water at high temperatures thatundergo de-polymerization.

Thus, there exists a need to develop different materials for use in FDMprinters and with varying robust properties, including having higherimpact strength, being non-moisture sensitive and not emitting VOC'sThere also exists a desire to produce other 3D materials with propertiesdifferent from the materials currently available on the market so thatmanufacturers and consumers can select the properties needed for the 3Dobject being created. In addition, there is always a desire to also findmore environmental friendly materials such as those derived fromrenewable resources. The ultimate goal is to find high quality, lowercost and “green” 3-D printing materials such that these printers maybecome more accessible and useful to the average consumer, as well asmanufacturers.

BRIEF SUMMARY

According to embodiments illustrated herein, there is provided asustainable three-dimensional printing material comprising a sustainableresin derived from a bio-based diacid and bio-based glycol monomer; acolorant; and an optional additive.

In certain embodiments, the disclosure provides a sustainablethree-dimensional printing material comprising: a sustainable resinderived from a bio-based succinic acid and bio-based 1,4-butane-diol asshown by the reaction scheme below:

wherein n is from about 100 to about 100,000; a colorant; and anoptional additive.

In yet further embodiments, there is provided a method of printingcomprising providing a thermoplastic filament, wherein the thermoplasticfilament further comprises a sustainable resin derived from a bio-baseddiacid monomer and bio-based glycol monomer, a colorant, and an optionaladditive; heating the thermoplastic filament to its melting point;extruding the melted thermoplastic filament layer by layer; and forminga three-dimensional object from the layers of melted thermoplasticfilament.

DETAILED DESCRIPTION

In the following description, it is understood that other embodimentsmay be used and structural and operational changes may be made withoutdeparting from the scope of the present disclosure.

Energy and environmental policies, increasing and volatile oil prices,and public/political awareness of the rapid depletion of global fossilreserves have created a need to find sustainable monomers derived fromrecycled plastics and biomaterials. Such monomers can be used for a widefield of applications.

The present embodiments disclose a sustainable material suitable for 3-Dprinting including a resin obtained from the fermentation of bio-basedmaterials. The present embodiments derive a sustainable resin from thefermentation of glucose derived from corn or corn starch. As will bediscussed more fully below, the resin has demonstrated desirableproperties for use in 3D printing.

The terms “optional” or “optionally” as used herein means that thesubsequently described event or circumstance can or cannot occur, andthat the description includes instances where a said event orcircumstance occurs and instances where it does not.

The terms “three-dimensional printing system,” “three-dimensionalprinter,” “printing,” and the like generally describe various solidfreeform fabrication techniques for making three-dimensional objects byselective deposition, jetting, and fused deposition modeling.

The term “freezing” as used herein refers to the solidifying, gelling orhardening of a material during the three dimensional printing process.

The term “sustainable” includes recycled or recyclable materials as wellas biomass or bio-derived or bio-based materials. There materials aregenerally considered environmentally friendly. The terms “bio-derived”or “bio-based” are used to mean a resin comprised of one or moremonomers that are derived from plant material. By using bio-derivedfeedstock, which are renewable, manufacturers may reduce their carbonfootprint and move to a zero-carbon or even a carbon-neutral footprint.Bio-based polymers are also very attractive in terms of specific energyand emission savings. Utilizing bio-based feedstock can help provide newsources of income for domestic agriculture, and reduce the economicrisks and uncertainty associated with reliance on petroleum importedfrom unstable regions.

The sustainable resin of the present embodiments may be derived frombio-based diacid and a bio-based glycol. Examples of the bio-baseddiacid employed for producing the present bio-derived resin includes,but are not limited to, succinic acid, 2,5-furandicarboxylic acid,itaconic acid and mixtures thereof. Examples of bio-based glycolsemployed for producing the present bio-derived resin includes, but arenot limited to, 1,4-butane-diol, 1,3-propane-diol, 1,2-propanediol andmixtures thereof.

In a specific embodiment, the diacid is a bio-based succinic acid andthe glycol is a bio-based 1,4-butane-diol. In such embodiments, thesuccinic acid may be obtained from the fermentation of corn derivedglucose such as, for example, corn syrup. From this bio-based succinicacid, 1-4-butane-diol can then be derived by an hydrogenation reductionprocess. More specifically, bio-based succinic acid can be obtained by abacterial or a low pH yeast fermentation with downstream processing bydirect crystallization. In embodiments, the sustainable resin may beselected from the group consisting of poly-(butylene-succinate),poly-(butylene-2,5-furanate), poly-(butylene-itaconate),poly-(propylene-succinate), poly-(propylene-2,5-furanate),poly-(propylene-itaconate) and mixtures thereof. In one embodiment thesustainable resin is poly-butylene-succinate (PBS) produced through thereaction of bio-based succinic acid and 1,4-butane-diol as shown by thereaction scheme below:

wherein n is greater than 100, or from about 100 to about 100,000. Inthese embodiments, the weight average molecular weight of the resin isfrom about 10,000 grams/mole to about 500,000 grams/mole, or from about10,000 grams/mole to about 100,000 grams/mole. In the presentembodiments, the molecular weight and value of n need to be high so thatthe resulting resin is very hard and flexible, properties that aredesirable for printing of 3D objects. This requirement is different fromother printing technologies, such as for example, printing with tonerswhich only require simple printing on flat substrates like paper.

In some embodiments, the sustainable resin has a Young's ranging fromabout from about 0.5 gigapascals (GPa) to about 5 GPa, from about 1 GPato about 3 GPa, or from about 1 GPa to about 2 GPa.

In some embodiments, the sustainable resin has a Yield Stress rangingfrom about 10 megapascals (MPa) to about 100 MPa, from about 20 MPa toabout 80 MPa, from about 40 MPa to about 65 MPa, or from about 40 MPa toabout 60 MPa.

Young's modulus and Yield Stress can be measured using the 3300Mechanical Testing Systems available from Instron, by the ASTM 638Dmethod and using the sustainable resin filament of about 2 mm indiameter.

Based on the assessment of the mechanical properties of the filaments,there is reason to believe that the mechanical properties of anyresulting 3D structure printed from the resin filaments would be thesame. Thus, benefits of the present embodiments include reduced costsand the use of sustainable raw materials, and improved mechanicalproperties of structures printed with 3D Fused Deposition Modelling(FDM) printers using such raw materials.

In embodiments, the sustainable resins may be derived from about 45 toabout 55 percent by mole equivalent, from about 48 to about 52 percentby mole equivalent, or from about 49.5 to about 50.5 percent by moleequivalent of bio-based glycol, and from about 45 to about 55 percent bymole equivalent from about 48 to about 52 by mole equivalent, or fromabout 49.5 to about 50.5 by mole equivalent of the succinic acid,provided that the sum of both is 100 mole equivalent.

A sustainable resin described herein has a softening point and afreezing point consistent with the temperature parameters of one or more3D printing systems. In some embodiments, a sustainable resin has asoftening point ranging from about 120° C. to about 250° C., from about150° C. to about 200° C., or from about 155° C. to about 185° C. In someembodiments, a sustainable resin has a freezing point ranging from about10 C to about 100° C., from about 20° C. to about 75° C., or from about25° C. to about 60° C.

The softening point (Ts) of the sustainable resin, can be measured byusing the cup and ball apparatus available from Mettler-Toledo as theFP90 softening point apparatus and using the Standard Test Method (ASTM)D-6090. The measurement can be conducted using a 0.50 gram sample andheated from 100° C. at a rate of 1° C./min.

In some embodiments, the sustainable resin has a viscosity consistentwith the requirements and parameters of one or more 3-D printingsystems. In some embodiments, a bio-derived resin described herein has aviscosity ranging from about 100 centipoise to about 10,000 centipoise,from about 100 centipoise to about 1,000 centipoise, or from about 400centipoise to about 900 centipoise at a temperature of about 150° C.

In some embodiments, the sustainable resin has a viscosity consistentwith the requirements and parameters of one or more 3-D printingsystems. In some embodiments, a sustainable resin described herein has aviscosity ranging from about 200 centipoise to about 10,000 centipoise,from about 300 centipoise to about 5,000 centipoise, or from about 500centipoise to about 2,000 centipoise at a temperature of from about 100to about 200° C.

In some embodiments, a sustainable resin has a Tg of from about 50° C.to about 120° C., from about 60° C. to about 100° C., or from about 65°C. to about 95° C.

The glass transition Temperature (Tg) and melting point (Tm) of thesustainable resin, can be recorded using the TA Instruments Q1000Differential Scanning calorimeter in a temperature range from 0 to 150°C. at a heating rate of 10° C. per minute under nitrogen flow. Themelting and glass transition temperatures can be collected during thesecond heating scan and reported as the onset.

In some embodiments, the sustainable resin has a Young's ranging fromabout from about 0.5 gigapascals (GPa) to about 5 GPa, from about 1 GPato about 3 GPa, or from about 1 GPa to about 2 GPa.

In some embodiments, the sustainable resin has a Yield Stress rangingfrom about 10 megapascals (MPa) to about 100 MPa, from about 20 MPa toabout 80 MPa, from about 40 MPa to about 65 MPa, or from about 40 MPa toabout 60 MPa.

Young's modulus and Yield Stress can be measured using the 3300Mechanical Testing Systems available from Instron, by the ASTM 638Dmethod and using the sustainable resin filament of about 2 mm indiameter.

In some embodiments, a sustainable resin described herein isnon-curable. The sustainable resin described herein is biodegradable.

The sustainable resin can be melt blended or mixed in an extruder withother ingredients such as pigments/colorants.

Typically, the sustainable resin of the present embodiments is presentin the 3-D printing material in an amount of from about 85 to about 100percent by weight, or from about 90 to about 99 percent by weight, orfrom about 95 to about 100 percent by weight of the total weight of thematerial. To obtain a clear 3-D printing material, 100% of thesustainable resin of the present embodiments may be used. To obtain acolored 3-D printing material having a color such as black, cyan, red,yellow, magenta, or mixtures thereof, the material may contain fromabout 3% to about 15%, from about 4% to about 10%, or from about 5% toabout 8% of colorant by weight based on the total weight of thematerial. In certain embodiments, the sustainable 3-D printing materialconsist of two components namely a colorant and a sustainable resin ofthe present disclosure, as such the resin makes up the remainder amountby weight of the material.

The resulting sustainable 3-D printing material of the presentembodiments may include particles having a mean particle diameter offrom 10 micrometers to 10 meters, from 10 micrometers to 1 meters, orfrom 100 micrometers to 0.3 meters.

As described above, the 3-D printing material can further comprise acolorant, and/or one or more additives.

Colorants

Various suitable colorants of any color can be present in the 3-Dprinting materials, including suitable colored pigments, dyes, andmixtures thereof including REGAL 330®; (Cabot), Acetylene Black, LampBlack, Aniline Black; magnetites, such as Mobay magnetites MO8029™,MO8060™; Columbian magnetites; MAPICO BLACKS™ and surface treatedmagnetites; Pfizer magnetites CB4799™, CB5300™, CB5600™, MCX6369™; Bayermagnetites, BAYFERROX 8600™, 8610™; Northern Pigments magnetites,NP-604™, NP-608™; Magnox magnetites TMB-100™, or TMB-104™; and the like;cyan, magenta, yellow, red, green, brown, blue or mixtures thereof, suchas specific phthalocyanine HELIOGEN BLUE L6900™, D6840™, D7080™, D7020™,PYLAM OIL BLUE™, PYLAM OIL YELLOW™, PIGMENT BLUE 1™ available from PaulUhlich & Company, Inc., PIGMENT VIOLET 1™, PIGMENT RED 48™, LEMON CHROMEYELLOW DCC 1026™, E.D. TOLUIDINE RED™ and BON RED C™ available fromDominion Color Corporation, Ltd., Toronto, Ontario, NOVAPERM YELLOWFGL™, HOSTAPERM PINK E™ from Hoechst, and CINQUASIA MAGENTA™ availablefrom E.I. DuPont de Nemours & Company, and the like. Generally, coloredpigments and dyes that can be selected are cyan, magenta, or yellowpigments or dyes, and mixtures thereof. Examples of magentas that may beselected include, for example, 2,9-dimethyl-substituted quinacridone andanthraquinone dye identified in the Color Index as CI 60710, CIDispersed Red 15, diazo dye identified in the Color Index as CI 26050,CI Solvent Red 19, and the like. Other colorants are magenta colorantsof (Pigment Red) PR81:2, CI 45160:3. Illustrative examples of cyans thatmay be selected include, copper tetra(octadecyl sulfonamido)phthalocyanine, x-copper phthalocyanine pigment listed in the ColorIndex as CI 74160, CI Pigment Blue, and Anthrathrene Blue, identified inthe Color Index as CI 69810, Special Blue X-2137, and the like; whileillustrative examples of yellows that may be selected are diarylideyellow 3,3-dichlorobenzidene acetoacetanilides, a monoazo pigmentidentified in the Color Index as CI 12700, CI Solvent Yellow 16, anitrophenyl amine sulfonamide identified in the Color Index as ForumYellow SE/GLN, CI Dispersed Yellow 33 2,5-dimethoxy-4-sulfonanilidephenylazo-4′-chloro-2,5-dimethoxy acetoacetanilides, and PermanentYellow FGL, PY17, CI 21105, and known suitable dyes, such as red, blue,green, Pigment Blue 15:3 C.I. 74160, Pigment Red 81:3 C.I. 45160:3, andPigment Yellow 17 C.I. 21105, and the like, reference for example U.S.Pat. No. 5,556,727, the disclosure of which is totally incorporatedherein by reference.

The colorant, more specifically black, cyan, magenta and/or yellowcolorant, is incorporated in an amount sufficient to impart the desiredcolor to the 3-D printing material. In general, pigment or dye isselected, for example, in an amount of from about 1 to about 60 percentby weight, or from about 2 to about 10 percent by weight for color 3-Dprinting material, and about 3 to about 60 percent by weight for black3-D printing material.

Other Additives

Depending on the requirements of the final 3D object to be formed, otheradditive materials may be included in the 3D printing material. Forexample, specific fillers or conductive materials may be included. Inspecific embodiments, certain metals may be included as additives forprinting electronic parts or circuit boards. In such embodiments, theamount of additives present in the 3D printing material may be fromabout 5 to about 40 by weight of the total weight of the 3D printingmaterial.

The sustainable 3-D printing material of the present embodiments can beprepared by a number of known methods including melt mixing andextrusion of the sustainable resin, and an optional pigment particles orcolorants.

In an embodiment, a method of printing using the sustainable resincomprises providing a thermoplastic filament, wherein the thermoplasticfilament further comprises a sustainable resin; and a colorant, whereinthe sustainable resin is derived from a bio-based succinic acid andbio-based glycol (1,4-butane-diol) oligomer; heating the thermoplasticfilament to its melting point; extruding the melted thermoplasticfilament layer by layer; and forming a three-dimensional object from thelayers of melted thermoplastic filament. A FDM printing machine has thecapability of being heated up to 250° C. In embodiments, the heatingstep for the present method is conducted at a temperature of from about160 to about 260° C., or from about 180 to about 240° C., or from about200 to about 220° C. These temperature ranges are selected to provide aviscosity appropriate for jetting the layers required to form the 3Dobject. In further embodiments, the method comprises cooling andsolidifying the formed three-dimensional object. Depending on the 3Dobject to be formed, the number of layers printed may range from about10 to about 100,000, or from about 100 to about 100,000.

Other methods include those well known in the art such as flow ableextrudate, with or without agitation, and brought to the desiredoperating temperature, typically above the initial melting temperatureof the polymer, and then extruded and drawn to obtain the desiredmolecular orientation and shape.

EXAMPLES

The examples set forth herein below are illustrative of differentcompositions and conditions that can be used in practicing the presentembodiments. All proportions are by weight unless otherwise indicated.It will be apparent, however, that the present embodiments can bepracticed with many types of compositions and can have many differentuses in accordance with the disclosure above and as pointed outhereinafter. The synthesis of PBS resins of varying molecular weightsare described below:

Example 1 Synthesis of Sustainable Resin: Polybutylene-Succinate

Succinic acid (295.29 g), 1,4-butane-diol (293.18 g) and FASCAT 4100(2.01 g) was charged into a 1 Liter Parr reactor equipped with amechanical stirrer, distillation apparatus and bottom drain valve. Themixture was heated to 160° C. under a nitrogen purge (1 scfh), and thenslowly increased to 190° C. over a 3 hour period and maintained for anadditional 19 hours, during which time; water was collected as thebyproduct. The reaction temperature was then increased to 205° C. andthen vacuum was applied to remove the excess 1,4-butanediol to allowfurther polycondensation. The mixture was then heated at 225° C., whilstunder vacuum, until a viscosity of 418.5 cps at 150° C. was obtained.

Example 2 Synthesis of Sustainable Resin: Polybutylene-Succinate

Succinic acid (295.30 g), 1,4-butane-diol (293.11 g) and FASCAT 4100(2.01 g) was charged into a 1 Liter Parr reactor equipped with amechanical stirrer, distillation apparatus and bottom drain valve. Themixture was heated to 160° C. under a nitrogen purge (1 scfh), and thenslowly increased to 195° C. over a 3 hour period and maintained for anadditional 19 hours, during which time; water was collected as thebyproduct. The reaction temperature was then increased to 205° C. andthen vacuum was applied to remove the excess 1,4-butanediol to allowfurther polycondensation. Whilst under vacuum, the mixture was thenheated at 250° C., until a viscosity of 336.8 cps at 165° C. wasobtained.

Higher viscosity and molecular weights can be obtained by prolonging thepolycondensation reaction.

Example 3 Synthesis of Sustainable Resin: Polybutylene-Succinate

Succinic acid (591.05 g), 1,4-butane-diol (587.5 g) and FASCAT 4100(4.01 g) was charged into a 2 Liter Parr reactor equipped with amechanical stirrer, distillation apparatus and bottom drain valve. Themixture was heated to 160° C. under a nitrogen purge (1 scfh), and thenslowly increased to 190° C. over a 3 hour period and maintained for anadditional 3 hours, during which time; water was collected as thebyproduct. The mixture temperature was reduced to 140° C. and maintainedfor 19 hours. Then the reaction temperature was then increased to 205°C. and vacuum was applied to remove the excess 1,4-butanediol to allowfurther polycondensation. Whilst under vacuum, the mixture was thenheated at 225° C., and more FASCAT 4100 (1.03 g) was added to speed upreaction. The experiment monitored by viscosity measurement, and wasdischarged when viscosity reached 381 cps at 150° C.

Example 4 Synthesis of Sustainable Resin: Polybutylene-Succinate

Succinic acid (295.2 g), 1,4-butane-diol (338.05 g) and FASCAT 4100 (1.5g) was charged into a 1 Liter Parr reactor equipped with a mechanicalstirrer, distillation apparatus and bottom drain valve. The mixture washeated to 160° C. under a nitrogen purge (1 scfh), and then slowlyincreased to 190° C. over a 3 hour period and maintained for anadditional 3 hours, during which time; water was collected as thebyproduct. The reaction temperature was then increased to 210° C. andthen vacuum was applied to remove the excess 1,4-butanediol to allowfurther polycondensation. The mixture was then heated at 225° C., whilstunder vacuum, until a viscosity of 32 cps at 120° C. was obtained.

Table 1 shows a comparison of several properties between PLA and PBS.

Table 2 shows a comparison of filament properties between the PBSsamples and controls.

TABLE 1 Comparison of Properties of PLA and PBS Properties PLA PBS Glasstransition temperature (° C.) 55 −32 Melting point (° C.) 170-180 114Heat distortion temperature (° C.) 55 97 Tensile strength (Mpa) 66 34Elongation at break (%)  4 560 Izod impact strength (J/m) 29 300 Degreeof crystallinity (%) — 35-45

TABLE 2 Filament Properties Yield stress Yield strain Breaking stressResin Filaments (MPa) (%) (MPa) Control: ABS Natural 41.62 4.85 20.16Control: PLA True Black 67.87 5.31 28.82 Example 1 28.44 6.3 16.25Example 2 35.31 16.78 19.54

Preparation of 3-D Printing Material

Resin filaments from Examples 1 to 4, were prepared using the Melt FlowIndex (MFI) instrument. The sample of each of the resins obtained fromwere melted separately in a heated barrel and extruded through anorifice of a specific diameter, under a certain weight. The resultingresin filaments are flexible and hard. The mechanical properties of theresin filaments were measured using the Instron Tensile Testing Systemand compared with the commercial ABS (acrylonitrile butadiene styrene)and PLA (Example 3) 3-D materials. Table 2 below shows the yield stress,yield strain, breaking strain and breaking stress for the Resinfilaments of Example 1 to 4 and the controls ABS and PLA (true blackcolor).

What is claimed is:
 1. A method of printing comprising providing athermoplastic filament, wherein the thermoplastic filament furthercomprises a sustainable resin derived from a bio-based diacid monomerand bio-based glycol monomer, wherein when the sustainable resin ispolybutylene succinate, the weight average molecular weight of thesustainable resin is from about 10,000 grams/mole to about 500,000grams/mole; further wherein the polybutylene succinate is producedthrough the reaction of bio-based succinic acid and 1,4-butane-diol asshown by the reaction scheme below:

wherein n is from about 100 to about 100,000; a colorant, and anoptional additive; heating the thermoplastic filament to its meltingpoint; extruding the melted thermoplastic filament layer by layer; andforming a three-dimensional object from the layers of meltedthermoplastic filament.
 2. The method of claim 1, wherein the heatingstep is conducted at a temperature of from about 160 to about 260° C. 3.The method of claim 1, wherein the sustainable resin is derived fromabout 48 to about 52 percent by mole equivalent of bio-based diacidmonomer, and from about 48 to about 52 percent by mole equivalent of thebio-based glycol monomer, provided that the sum of both is 100 percent.4. The method of claim 1 further comprising cooling and solidifying theformed three-dimensional object.
 5. The method of claim 1, wherein thethree-dimensional printing material having a Young's Modulus of fromabout 0.5 to about 5 gigapascals.
 6. The method of claim 1, wherein thethree-dimensional printing material having a Yield Stress of from about10 to about 100 megapascals.